Heat-resistant thermoplastic molding compositions

ABSTRACT

Thermoplastic molding compositions suitable for producing interior components for vehicles for the conveyance of passengers, in particular aircraft, which show a low smoke gas density and low heat release characteristics in the event of a fire, are based on a heat-resistant plastic which contains as a filler from 0.5 to 50% by weight of an oxide of an element of main group III, IV or V, of a salt of an oxygen acid of an element of main group III, IV or V or of a compound which on heating forms such an oxide or salt.

This is a division of application Ser. No. 07/394,970, filed on Aug. 17,1989 now U.S. Pat. No. 4,981,895.

The present invention relates to heat-resistant thermoplastic moldingcompositions of low heat release in the event of fire which are suitablefor producing interior components for vehicles for the conveyance ofpassengers, in particular aircraft.

The insides of aircraft are constructed with the use of moldings made ofthermoplastics. Hitherto, ABS polymers, polyvinyl chloride orpolycarbonates have been used for this purpose. However, in the event ofa fire these materials release a lot of heat, toxic gases and smoke ofhigh optical density in particular in the critical first 5 minutes afterthe fire has started. Plastics which are resistant at high temperatures,for example polyether sulfones, do not have this disadvantage; in theevent of a fire their smoke gas density is low and they form only smallamounts of toxic gases. They meet the Airbus Technical SpecificationATS/1000.001. On the other hand, they do not quite meet the tougherstandards for heat release in the event of a fire. These have recentlybeen laid down by the Federal Aviation Administration (FAA). For 1988they provide that the values for heat release (HR) and heat release rate(HRR) (measured by the FAA's FAR test no. 25 853 of Feb. 20, 1987) mustbe below 100 kW.min.m⁻² and below 100 kW.m⁻² respectively; from 1990 thevalues should be less than 65 kW.min.m⁻² and less than 65 kW.m⁻²respectively.

It is an object of the present invention to provide thermoplasticmolding compositions which in the event of a fire have a low smoke gasdensity, release small amounts of toxic combustion gases and meet theFAA's tightened-up conditions concerning heat release.

We have found that this object is achieved by adding certain oxides orsalts of elements of main groups III to V to aromatic thermoplasticswhich are resistant at high temperatures.

The present invention accordingly provides a thermoplastic moldingcomposition containing

A. 100 parts by weight of a heat-resistant aromatic thermoplastic havinga sustained use temperature of above 130° C. and

B. from 0.5 to 50 parts by weight

a) of an oxide of an element of main group III, IV or V, or

b) of a salt of an oxygen acid of an element of main group III, IV or V,each with a melting point of from 300° C. to 1400° C., or

c) of a compound which on heating forms an oxide a) or a salt b).

Suitable heat-resistant plastics A are those having a sustained usetemperature (as defined in UL 746 B) of above 130° C., preferably ofabove 150° C. Preference is given to polyether sulfones, in particularthose of the structures: ##STR1## polyether ketones, in particular thoseof the structures: ##STR2## polyether imides of the structure ##STR3##polyphenylene sulfide of the structure ##STR4## liquid-crystallinepolyesters, in particular those based on terephthalic acid, hydroquinoneand p-hydroxybenzoic acid: thermoplastic polyimides of the structure##STR5## thermoplastic polyamide imides of the structure ##STR6## andcorresponding random and block copolymers and mixtures of two or more ofthese polymers.

These polymers contain according to the invention from 0.5 to 50 partsby weight, preferably from 0.5 to 20 parts by weight and in particularfrom 1 to 5 parts by weight, of a filler B which inhibits the release ofheat in the event of a fire. Particular preference is given to thoseinorganic fillers which on cooling turn from a molten state into anamorphous, glassy state, forming a two- or three-dimensional networkstructure which can wet the molten polymer and cover it with a layer ofmelt. Filler B can preferably be strongly absorptive or reflective of IRradiation. It is possible to use oxides of elements of main groups IIIto V of the periodic table and salts, preferably Na-, K-, Ca-, Zn- orAl-salts, of oxygen acids of an element of main group III, IV, or V,provided they have a melting point of 300° C. to 1400° C., preferably of350° C. to 1200° C., in particular from 400° C. to 1000° C., and ofcompounds, for example hydrates or carbonates, which in the event of afire (for example at from about 500° C.) form such an oxide or salt. Itis also possible to produce mixtures of the types of substancesmentioned.

Suitable fillers are for example: B₂ O₃, NaBO₂, KB₅ P₈, Na₂ B₄ O₇,Ca(BO₂)₂, Zn(BO₂)₂ ; Zn₂ B₆ O₁₁, P₂ O₅, NaPO₃, Na₄ P₂ O₇ ; Ca(PO₃)₂, Zn₃(PO₄)₂ ; K₃ (ArO₃)₃ ; Sb₂ O₃, Sb₂ O₅, Na₃ SbO₄ ; NaSiO₃ (water glass),Na₂ O.CaO.6 SiO₂, K₂ O.Al₂ O₃.6 SiO₂ (feld spar), Na₂ O.Al₂ O₃.6 SiO₂(zeolite) and other silicates.

In addition to these fillers, which prevent heat release in the event ofa fire, the molding compositions may contain other, customary additives,for example glass fibers, carbon fibers, pigments, mineral reinforcingagents, toughness modifiers, for example siloxanes, fluoroelastomers,polyphosphogenes, stabilizers and lubricants. The fibrous additives maybe used as unidirectional laid fabrics, as woven fabrics, as knittedfabrics or as nonwovens.

The fillers and any further additives are incorporated in a conventionalmanner. Preferably, the fillers are used in the form of finely groundpowders and are for example mixed with the plastic in an extruder.However, it is also possible to incorporate solutions or suspensions ofthe salts.

In the case of B₂ O₃, a master batch can be prepared from filler andpolymer melt.

The molding compositions according to the invention are suitable inparticular for producing interior components of vehicles for theconveyance of passengers, for example films, coverings, injectionmoldings, sheets or composites, for example with foams. Besides aircraftinterior components, the molding compositions are also suitable forcomponents for high speed trains, coaches or subway trains.

The moldings are produced in a conventional manner by extrusion, deepdrawing, injection molding, laminating, welding or adhesive bonding. Themoldings can be coated with lacquers or covered with dirtrepellentfilms. Extruded sheets can be covered by coextrusion with a layer whichcontains the oxides or salts in a high concentration. They are notablefor low HR or HRR values of less than 65, preferably less than 60,kW.min.m⁻² or kW.m⁻².

In the Examples, the percentages are by weight. Incorporation is bycompounding of finely pulverulent filler into the respectivethermoplastic on an extruder.

Heat release was measured on 2-mm thick sheets in terms of HR(kW.min.m⁻²) and HRR (kW.m⁻²); the tables show averages of 4measurements.

EXAMPLE 1

Filler: Sb₂ O₃ ; thermoplastic: polyether sulfone ULTRASON® E 1000 fromBASF; incorporation temperature: 370° C.

    ______________________________________                                        % of Sb.sub.2 O.sub.3                                                                          HR     HRR                                                   ______________________________________                                        0                30     68                                                    1                14     64                                                    3                10     59                                                    5                3      53                                                    ______________________________________                                    

EXAMPLE 2

Filler: Zn₂ B₆ O₁₁ ; thermoplastic: polysulfone ULTRASON® E;incorporation temperature: 370° C.

    ______________________________________                                        % of Zn.sub.2 B.sub.6 O.sub.11                                                                   HR     HRR                                                 ______________________________________                                        0                  30     68                                                  1                  8      57                                                  3                  7      48                                                  5                  6      45                                                  ______________________________________                                    

EXAMPLE 3

The HRR and HR values of filled and unfilled polyether sulfone ULTRASON®E 2000 white 20126 were measured on 2-mm thick sheets; incorporationtemperature: 370° C.

    ______________________________________                                                         HRR      HR                                                  % of filler      kWm.sup.-2                                                                             kW min m.sup.-2                                     ______________________________________                                        0                66       22                                                  5% of Sb.sub.2 O.sub.5                                                                         49       24                                                  3% of B.sub.2 O.sub.3                                                                          56       9                                                   5% of B.sub.2 O.sub.3                                                                          50       3                                                   4% of Ca phosphate                                                                             58       2                                                   4% of Ca silicate                                                                              57       0                                                   4% of K pentaborate                                                                            62       29                                                  ______________________________________                                    

EXAMPLE 4

HRR and HR values of thermoplastics filled with zinc borate

    __________________________________________________________________________               Zn.sub.2 B.sub.6 O.sub.11                                                           Incorporation temp.                                                                     Sheet thickness                                                                       HRR   HR                                   Thermoplastic                                                                            %     °C.                                                                              mm      kW · m.sup.-2                                                              kW · min ·                                                  m.sup.-2                             __________________________________________________________________________    ULTEM ® 1000                                                                         1     350       2.2     50    10                                   ULTEM ® 1000                                                                         3     350       2.2     49    3                                    ULTEM ® 1000                                                                         5     350       2.2     46    3                                    ULTRAPEK ® 4177                                                                      --    390       2.3     69    0                                    ULTRAPEK ® 4177                                                                      4     390       2.3     49    0                                    RYTON ® P 4                                                                          --    320       2.1     78    7                                    RYTON ® P 4                                                                          4     320       2.1     64    4                                    __________________________________________________________________________     ULTEM ® 1000 is a polyether imide from General Electric                   ULTRAPEK ® is a polyether ketone from BASF                                RYTON ® is a polyphenylene sulfide from Phillips                     

We claim:
 1. An aircraft interior component based on a filler-containingheat-resistant thermoplastic molding composition, which in the event ofa fire has a heat release value of less than 65 kW.min.m⁻² at a heatrelease rate of less than 65 kW.m⁻², both measured by FAR test 25 853,comprising:A. 100 parts by weight of a polyether imide having asustained use temperature of above 130° C.; and B. from 0.5 to 50 partsby weight(a) of an oxide or boron, silicon, phosphorous, or arsenic, or(b) of a salt of an oxygen acid of boron, silicon, phosphorous, orarsenic,each with a melting point of from 300° C. to 1400° C., or (c) ofa compound which on heating forms an oxide a) or a salt b) wherein saidoxides or salts are in the form of a finally ground powder.
 2. Theaircraft interior component based on a filler-containing heat resistantthermoplastic molding composition as claimed in claim 1, whereincomponent B is selected from the following compounds:B₂ O₃, NaBO₂, Na₂B₄ O₇, KB₅ O₈, Ca(BO₂)₂, Zn₂ B₆ O₁₁, Zn(BO₂)₂ ; K₃ (AsO₃)₃ ; P₂ O₅,NaPO₃, Na₄ P₂ O₇, Ca(PO₃)₂, Zn₃ (PO₄)₂ ; Na₂ SiO₃, Na₂ O.CaO.6 SiO₂, 2K₂ O.Al₂ O₃.6 SiO₂.
 3. The aircraft interior component based on afiller-containing heat-resistant thermoplastic molding composition asclaimed in claim 1, wherein component B is a compound which on coolingturns from a molten state into an amorphous, glossy state.
 4. Anaircraft interior component based on a filler-containing heat-resistantthermoplastic molding composition, which in the event of a fire has aheat release value of less than 65 kW.min.m⁻² at a heat release rate ofless than 65 kW.m⁻², both measured by FAR test 25 853, comprising:A. 100parts by weight of a polyether imide having a sustained use temperatureof above 130° C.; and B. from 0.5 to 50 parts by weight(a) of an oxideof boron, silicon, phosphorous, arsenic or antimony, or (b) of a salt ofan oxygen acid of boron, silicon, phosphorous, arsenic, or antimony,eachwith a melting point of from 300° C. to 1400° C., or (c) of a compoundwhich on heating forms an oxide a) or a salt b) wherein said oxides orsalts are in the form of a finally ground powder.